Screening apparatus for removing solid material from flowing liquid and associated screening panel

Abstract

A screening panel for an apparatus for removing solid material from a flowing liquid, where the screening panel is mountable to a conveyor of the apparatus for travel around an endless path passing into and out of the flowing liquid. The screening panel is molded from a polymeric material and provided with a plurality of apertures each extending through the screening panel from a first major surface to an opposing second major surface. The apertures each have a tapered hexagonal cross-section.

What is claimed is: 
     
         1 . A screening apparatus for removing solid material from a flowing liquid, comprising:
 a plurality of screening panels;   a conveyor, the screening panels being mounted to the conveyor for travel around an endless path passing into and out of the flowing liquid;   each of the screening panels having a first major surface and a second major surface in parallel relation to one another, each of the screening panels being mounted to the conveyor so that the first major surface faces the flowing liquid, and the second major surface faces in a direction of flow of the flowing liquid, and each screening panel being molded from a polymeric material and being provided with a plurality of apertures; and   the apertures each extending through each panel from the first major surface to the second major surface to thereby permit liquid flow through the apertures, the apertures each having a hexagonal cross-section in at least one of the first major surface and the second major surface, each of the apertures having a first maximum transverse dimension at the first major surface with a transverse dimension increasing progressively from the first major surface towards the second major surface, each of the apertures having a second maximum transverse dimension greater than the first maximum transverse dimension at the second major surface of the respective screening panel.   
     
     
         2 . The apparatus defined in  claim 1  wherein the screening panels each have a thickness of approximately 9 mm and wherein the apertures have a taper of 0.3 to 0.5 mm from the second major surface to the first major surface. 
     
     
         3 . The apparatus defined in  claim 1  wherein each of the apertures has a first maximum transverse dimension of 3.3 mm, vertex to opposing vertex, at the second major surface and a second maximum transverse dimension of 3 mm, vertex to opposing vertex, at the first major surface. 
     
     
         4 . The apparatus defined in  claim 1  wherein the apertures are equispaced from each neighboring one of the apertures. 
     
     
         5 . The apparatus defined in  claim 1  wherein the apertures form a honeycomb grid or pattern, each of the apertures internal to the grip or pattern having six angularly equispaced neighbor apertures. 
     
     
         6 . The apparatus defined in  claim 1  wherein each of the screening panels provides an increase in aggregate flow-through area of 9-16% over a screening panel of equal size having conical or cross-sectionally circular apertures. 
     
     
         7 . The apparatus defined in  claim 1  wherein the apertures have a hexagonal cross-section along their entire lengths from the first major surface to the second major surface. 
     
     
         8 . A screening panel for an apparatus for removing solid material from a flowing liquid, where the screening panel is mountable to a conveyor for travel around an endless path passing into and out of the flowing liquid, the screening panel comprising:
 a first major surface and a second major surface in parallel relation to one another,   said screening panel being molded from a polymeric material and provided with a plurality of apertures,   the apertures each extending through said screening panel from the first major surface to the second major surface to thereby permit liquid flow through the apertures,   the apertures each having a hexagonal cross-section in at least one of the first major surface and the second major surface,   each of the apertures having a first maximum transverse dimension at the first major surface with a transverse dimension increasing progressively from the first major surface towards the second major surface,   each of the apertures having a second maximum transverse dimension greater than the first maximum transverse dimension at the second major surface.   
     
     
         9 . The screening panel defined in  claim 8  wherein said first major surface and said second major surface are spaced by a panel thickness of approximately 9 mm and wherein the apertures have a taper of 0.3 to 0.5 mm from the second major surface to the first major surface. 
     
     
         10 . The screening panel defined in  claim 8  wherein each of the apertures has a first maximum transverse dimension of 3.3 mm, vertex to opposing vertex, at the second major surface and a second maximum transverse dimension of 3 mm, vertex to opposing vertex, at the first major surface. 
     
     
         11 . The screening panel defined in  claim 8  wherein the apertures are equispaced from each neighboring one of the apertures. 
     
     
         12 . The screening panel defined in  claim 8  wherein the apertures form a honeycomb grid or pattern, each of the apertures internal to the grip or pattern having six angularly equispaced neighbor apertures. 
     
     
         13 . The screening panel defined in  claim 8  wherein said screening panel provides an increase in aggregate flow-through area of 9-16% over a screening panel of equal size having conical or cross-sectionally circular apertures. 
     
     
         14 . The screening panel defined in  claim 8  wherein the apertures have a hexagonal cross-section along their entire lengths from the first major surface to the second major surface.